package double_pointer;

public class compareVersion {
    public int compareVersion(String version1, String version2) {
        int n = version1.length(),m = version2.length();
        int i =0,j = 0;
        while(i < n || j < m) {
            int x = 0;
            for(;i < n && version1.charAt(i) != '.';i++) {
                x = x*10 + (version1.charAt(i)- '0');
            }
            //跳过 . 号
            i = i +1 ;

            int y = 0;
            for(;j < m && version2.charAt(j) != '.';j++) {
                y = y*10 + (version2.charAt(j)- '0');
            }
            //跳过 . 号
            j = j +1 ;

            if(x != y) {
                if(x > y) {
                    return 1;
                }else {
                    return -1;
                }
            }
        }

        return 0;
    }
}
